while its possible its due to battery voltage..issues like that usually occur right after start up or at least near it. as for 9k a year...that should be enough milage per year. however, if the car sits for long periods of time and then is driven for say long trips(ie car sits for a month then is driven 2k in a week..then sits another 3 weeks) then id recommend a battery tender. we goodwill those things all the time at my shop..